Research on the Doppler ground simulation system based on spatial coherence laser communication link

Abstract Spatial coherence laser communication, characterized by its high-speed data transmission and strong resistance to interference, has emerged as a pivotal technology for future high-speed inter-satellite communication. In satellite laser communication terminals, the Doppler effect caused by high-speed relative movement between satellites significantly affects the performance of the communication link. To address this issue, this paper proposes a Doppler frequency-shift simulation system based on the electro-optic effect of lithium niobate modulators combined with tunable optical filtering. This system introduces a linear frequency modulation signal. By adjusting the relevant module parameters in the OptiSystem software environment, it can simulate the variation characteristics of the communication optical center wavelength during the satellite’s relative acceleration or deceleration motion under different accelerations, with a sideband suppression ratio greater than 45 dB. This work provides an effective technical approach for simulating and compensating Doppler effects in inter-satellite coherent laser communication systems.